Process for regenerating a catalyst

Abstract

A process for regenerating one or more deactivated cobalt comprising Fischer-Tropsch catalyst particle(s) in situ in a reactor tube, said process comprising the steps of: (i) oxidising the catalyst particle(s) at a temperature between 20 and 400° C.; (ii) treating the catalyst particle(s) for more than 5 minutes with a solvent, (iii) drying the catalyst particle(s); and (iv) optionally reducing the catalyst with hydrogen or a hydrogen comprising gas. This process may be preceded by a step in which Fischer-Tropsch product is removed from the catalyst particle(s).

1 . A process for regenerating one or more cobalt comprising Fischer-Tropsch catalyst particles in situ in a reactor tube, said catalyst particle(s) having been deactivated by use in a Fischer-Tropsch process, said process for regenerating comprising the steps of:
 (i) oxidizing the catalyst particle(s) in situ at a temperature between 20 and 400° C.;   (ii) treating the catalyst particle(s) for more than 5 minutes with a solvent,   (iii) drying and heating the catalyst particle(s); and   (iv) reducing the catalyst particle(s) with hydrogen or a hydrogen comprising gas.   
   
   
       2 . A process according to  claim 1 , wherein the treatment step (ii) comprises the steps of:
 (ii)(a) filling pores of the catalyst particle(s) with a solvent at a temperature in the range of from 5 to 40° C. using a pore fill method; and   (ii)(b) leaving the solvent in the pores for more than 5 minutes at a temperature between 5 and 90° C.   
   
   
       3 . A process according to  claim 1 , wherein the catalyst particle(s) is/are partially reduced with hydrogen or a hydrogen comprising gas after the oxidation step (i) and before the treatment step (ii). 
   
   
       4 . A process according to  claim 1 , wherein step (i) is preceded by a step in which Fischer-Tropsch synthesis product is removed from the Fischer-Tropsch catalyst particle(s), preferably by washing the catalyst particle(s) with petroleum gas oil or a synthetic gas oil. 
   
   
       5 . A process according to  claim 1 , wherein step (ii) is performed while excluding oxygen or any other oxidant-containing gas from the part of the catalyst particle(s) that is/are being treated. 
   
   
       6 . A process according to  claim 1 , wherein the solvent used in step (ii) comprises one or more chemical compounds selected from the group consisting of nitric acid, weak organic acids, ammonium salts, and alkyl ammonium salts. 
   
   
       7 . A process according to  claim 1 , wherein the solvent used in step (ii) comprises one or more chemical compounds selected from the group consisting of glycine, ammonium carbonate, a mixture of glycine and ethylene diamine, a mixture of glycine and ammonium hydroxide, and a mixture of ammonium carbonate and ammonium hydroxide. 
   
   
       8 . A process according to  claim 6 , wherein the solvent used in step (ii) additionally comprises water. 
   
   
       9 . A process according to  claim 7 , wherein the solvent used in step (ii) comprises a mixture of ammonium carbonate, ammonium hydroxide and water, with a weight ratio of the ammonium hydroxide to the ammonium carbonate in the range of from 1:0.25 to 1:2. 
   
   
       10 . A process according to  claim 7 , wherein the solvent used in step (ii) comprises a mixture of ammonium carbonate, ammonium hydroxide and water, with a weight ratio of the ammonium carbonate to water in the range of from 1:0.5 to 1:4. 
   
   
       11 . A process according to  claim 7 , wherein the solvent used in step (ii) comprises a mixture of ammonium carbonate, ammonium hydroxide and water, with a weight ratio of the ammonium hydroxide to water in the range of from 1:0.25 to 1:4. 
   
   
       12 . A process according to  claim 1 , wherein the catalyst particle(s) is/are fixed bed particle(s) larger than 1 mm or immobilized slurry particle(s) larger than 1 mm, and the treatment step (ii) is performed using a pore fill method, and 85% or less of the catalyst particle(s) are treated, whereby the part of the catalyst particle(s) located at the upstream end is not or is hardly subjected to the treating step (ii). 
   
   
       13 . A process according to  claim 12 , wherein at least 20% of the catalyst particle(s) are treated, whereby the part of the catalyst particle(s) located at the downstream end is subjected to the treating step (ii). 
   
   
       14 . A regenerated catalyst particle obtained by the process of  claim 1 . 
   
   
       15 . A process according to  claim 5  wherein step (ii) is performed using an inert gas. 
   
   
       16 . A process according to  claim 6  wherein the solvent further comprises one or more compounds selected from the group consisting of ammonia, ammonium hydroxide, ethylene diamine and urea. 
   
   
       17 . A process for regenerating one or more cobalt comprising Fischer-Tropsch catalyst particles in situ in a reactor tube, said catalyst particle(s) having been deactivated by use in a Fischer-Tropsch process, said process for regenerating comprising the steps of:
 (i) oxidizing the catalyst particle(s) in situ at a temperature between 20 and 400° C.;   (ii) treating the catalyst particle(s) for more than 5 minutes with a solvent wherein the solvent comprises one or more chemical compounds selected from the group consisting of nitric acid, weak organic acids, ammonium salts, and alkyl ammonium salts,   (iii) drying and heating the catalyst particle(s); and   (iv) reducing the catalyst particle(s) with hydrogen or a hydrogen comprising gas.   
   
   
       18 . A process for regenerating one or more cobalt comprising Fischer-Tropsch catalyst particles in situ in a reactor tube, said catalyst particle(s) having been deactivated by use in a Fischer-Tropsch process, said process for regenerating comprising the steps of:
 (i) oxidizing the catalyst particle(s) in situ at a temperature between 20 and 400° C.;   (ii) treating the catalyst particle(s) for more than 5 minutes with a solvent wherein the solvent comprises one or more chemical compounds selected from the group consisting of glycine, ammonium carbonate, a mixture of glycine and ethylene diamine, a mixture of glycine and ammonium hydroxide, and a mixture of ammonium carbonate and ammonium hydroxide,   (iii) drying and heating the catalyst particle(s); and   (iv) reducing the catalyst particle(s) with hydrogen or a hydrogen comprising gas.